Senior Software Engineer

55 Exec Search; Greater London; Hybrid; GBP 90,000 - 140,000; Full time

Benefits offered by this job

Meaningful Equity

Hybrid Working

Opportunity to build an industry‑defin

Job summary

55 Exec Search is partnering with an ambitious AI start-up developing behavioural biometrics technology that redefines digital identity, authentication and cybersecurity. This role sits at the intersection of AI, cloud infrastructure, identity and security, where engineering decisions shape how intelligent systems are deployed and trusted by customers worldwide.

You’ll join a small, high-ownership engineering team as a Senior Software Engineer, owning software from architecture through to

Qualifications

• 5+ years’ commercial software engineering experience with clear progression in technical responsibility and ownership.
• Strong commercial experience with TypeScript across the stack, together with modern backend development (Node.js preferred).
• Experience working confidently across frontend, backend and cloud infrastructure.
• A proven track record of delivering complex software systems from technical design through deployment and production.
• Strong experience designing and building production REST APIs and service integrations.
• Commercial AWS experience (essential), together with Kubernetes, containers and cloud-native environments.
• Experience with CI/CD pipelines, observability, monitoring and production operations.
• Experience building software around AI or Machine Learning technologies, or integrating AI capabilities into production applications.
• Excellent communication skills with the ability to explain technical concepts to both engineering and non-technical stakeholders.

Responsibilities

• Design and deliver complex software systems from concept through to production.
• Translate product objectives into practical engineering solutions and realistic delivery plans.
• Design secure, scalable APIs, backend services and cloud-native infrastructure.
• Build production-ready software that integrates AI capabilities into customer-facing products.
• Work across frontend, backend, infrastructure and cloud services as the product demands.
• Make architectural decisions, documenting technical trade-offs and long-term design choices.
• Improve engineering standards through thoughtful code reviews, mentoring and technical leadership.
• Collaborate closely with AI Engineers to ensure AI capabilities operate reliably in production.
• Use AI-assisted development tools responsibly, applying engineering judgement to validate quality, security, maintainability and performance.

Skills

TypeScript

Node.js

REST APIs

AWS

Kubernetes

CI/CD

Cloud infrastructure

Tools

Docker

Job description

Hybrid (2-3 days onsite with flexibility)

We’re partnering with an ambitious AI start-up developing cutting-edge behavioural biometrics technology that’s redefining digital identity, authentication and cybersecurity.

This isn’t another SaaS platform.

This is software sitting at the intersection of AI, cloud infrastructure, identity and security, where engineering decisions directly influence how intelligent systems are deployed, scaled and trusted by customers around the world.

We’re looking for a Senior Software Engineer who enjoys solving difficult technical problems, influencing architecture and taking ownership from technical design through to production.

This is a role for engineers who don’t simply complete tickets, they own problems, challenge assumptions and take responsibility for delivering high-quality software.

What You’ll Be Building:

This isn’t a traditional Full Stack role focused solely on frontend and backend development.

You’ll contribute across the entire software platform, including:

• Customer-facing web applications
• Backend services and APIs
• Cloud-native infrastructure
• Authentication and security services
• AI-powered product capabilities
• Observability, monitoring and production operations

You’ll work across the full software lifecycle from architecture and development through deployment, monitoring and continuous improvement.

This role is likely to be a great fit if you:

• Have built software around AI or Machine Learning technologies or worked closely with AI Engineers to deliver AI-powered products into production.
• Enjoy designing scalable systems rather than simply implementing requirements.
• Naturally think about maintainability, resilience, security and long-term architecture.
• Thrive in startup or high-growth environments where priorities evolve, ambiguity exists and everyone contributes across multiple disciplines.
• Enjoy taking ownership of software from architecture through to deployment and production support.
• Prefer solving problems rather than waiting to be told exactly what to build.

You’ll Be Trusted To:

• Design and deliver complex software systems from concept through to production.
• Translate product objectives into practical engineering solutions and realistic delivery plans.
• Design secure, scalable APIs, backend services and cloud-native infrastructure.
• Build production-ready software that integrates AI capabilities into customer-facing products.
• Work across frontend, backend, infrastructure and cloud services as the product demands.
• Make architectural decisions, documenting technical trade-offs and long-term design choices.
• Improve engineering standards through thoughtful code reviews, mentoring and technical leadership.
• Collaborate closely with AI Engineers to ensure AI capabilities operate reliably in production.
• Use AI-assisted development tools responsibly, applying engineering judgement to validate quality, security, maintainability and performance.

What You’ll Bring:

We’re looking for an experienced engineer who can demonstrate most of the following:

• 5+ years’ commercial software engineering experience with clear progression in technical responsibility and ownership.
• Strong commercial experience with TypeScript across the stack, together with modern backend development (Node.js preferred).
• Experience working confidently across frontend, backend and cloud infrastructure.
• A proven track record of delivering complex software systems from technical design through deployment and production.
• Strong experience designing and building production REST APIs and service integrations.
• Commercial AWS experience (essential), together with Kubernetes, containers and cloud-native environments.
• Experience with CI/CD pipelines, observability, monitoring and production operations.
• Experience building software around AI or Machine Learning technologies, or integrating AI capabilities into production applications.
• Excellent communication skills with the ability to explain technical concepts to both engineering and non-technical stakeholders.

You’ll Stand Out If You’ve:

• Worked directly alongside AI Engineers or Machine Learning teams to deliver AI-powered products.
• Built software within behavioural biometrics, identity, authentication, cybersecurity or fraud prevention.
• Worked in a startup or high-growth technology company.
• Contributed to software architecture, engineering standards and technical direction.
• Built developer platforms, SDKs or highly scalable SaaS products.
• Worked with high-volume or real-time data processing, streaming platforms or distributed systems.

What Makes This Opportunity Different?

This isn’t a role where you’ll own one small component of a large engineering organisation.

You’ll join a small, highly technical team where you’ll:

• Influence architecture and engineering direction.
• Own software from technical design through production.
• Help define engineering standards and best practice.
• Work directly alongside AI Engineers solving complex real-world problems.
• Build software that enables cutting-edge AI to operate securely, reliably and at scale.
• Make technical decisions that have a visible impact on both the product and the business.

Salary & Benefits

• Meaningful Equity consideration
• Hybrid Working
• Opportunity to build an industry-defining AI platform
• High level of technical ownership and autonomy